Earthmoving machines such as track type tractors, motor graders, scrapers, and/or backhoe loaders, have an implement such as a dozer blade or bucket, which is used on a worksite in order to alter a geography or terrain of a section of earth. The implement may be controlled by an operator or by an autonomous grade control system to perform work on the worksite. For example, the operator may move an operator input device that controls the movement of the implement using one or more hydraulic actuators. To achieve a final surface contour or a final grade, the implement may be adjusted to various positions by the operator or the grade control system.
Positioning the implement, however, is a complex and time-consuming task that requires expert skill and diligence if the operator is controlling the movement. Thus, it is often desirable to provide the autonomous grade control system for the implement to simplify the operator control. Prior art systems that automatically control the implement are known. For example, U.S. Pat. No. 6,064,933 discloses an automatic control system for positioning the implement of an earthmoving machine in accordance with a stored sequence of control command signals.